CSS shaders
https://dvcs.w3.org/hg/FXTF/raw-file/tip/custom/index.html
This document describes a proposed feature called “CSS shaders”. CSS shaders are a complement to the Filter Effects specification and a solution for its feCustom element. In addition, CSS shaders introduce a notion of vertex shader into the filter model. The CSS shaders feature is proposed for consideration by the FX Task Force and could be integrated in the Filter Effects specification or made a separate module. This document is the result of ACTION-3072